Synthesis and characterization of a new coordination polymer of copper (II): Catalytic application for reductive degradation of dyes under dark

A new copper (II) coordination polymer [{Cu(TMDP)(2,3-pydc)}.2H₂O]_n (A) has been synthesized successfully by solvolysis method using ligands 4,4′-trimethylenedipyridine (TMDP) and 2,3-pyridinedicarboxylic acid (2,3-pydc). The structure of the synthesised coordination polymer is confirmed by the single crystal X-ray diffraction study and also supported by CHN analysis. FTIR, UV-visible spectroscopy, thermogravimetric analysis (TGA) and powder XRD study are used to characterize A. The polymer in aqueous solution is applied as effective catalyst for reductive degradation of methyl orange (MO) and Congo red (CR) dyes with reducing agent sodium borohydride (NaBH₄) under dark. The detail study of the catalytic reaction and its kinetic study reveals 97% and 76% degradation of MO and CR with rate constants of 0.061 min⁻¹ and 0.005 min⁻¹, respectively. This is the first example where a coordination polymer has been used for reductive degradation of dyes under dark condition.

Graphical abstract

A newly synthesized copper (II) coordination polymer [{Cu(TMDP)(2,3-pydc)}.2H₂O]_n (A) has been developed and studied by different analytical methods. The polymer (A) is then used as catalyst for degradation of anionic (MO and CR) dyes.